As shown in FIGS. 1 and 2, stations for storing, collecting and recirculating a fluid substance are currently known, which comprise:                a tank 11′ for storing the substance provided with a lower supply opening 12′ and an upper loading opening 13′; and        a circuit 14′ for recirculating the fluid substance contained in the tank 11.        
In particular, such recirculation circuit 14′ is provided with a first end associated with the lower supply opening 12, either directly or through a supply duct 24′, and a second end associated with the upper loading opening 13.
Between the first and the second end of the recirculation circuit 14′ a pump 15′ and an assembly of manual valves 16′ are provided.
The valve 16′ is associable with an external tank 17′ through a loading conduit 18′ and it is configurable for selectively defining the conditions of:                recirculation (FIG. 1) of the fluid substance contained in the tank 11′ along the recirculation circuit 14′ from the lower supply opening 12′ to the upper loading opening 13′ isolating the external tank 17′; and        loading (FIG. 2) the fluid substance from the external tank 17′ to the tank 11′ isolating the lower supply opening 12′ of the tank 11′.        
In other words, in the condition of loading, the valve 16′ closes the part upstream of the circuit 14′.
However, given that the substance stored in the external tank 17′ usually remains stationary for a long time before being loaded into the tank 11′, such external tank 17′ usually coming from very distant places with respect to the stations, the use of mechanical agitators to be previously inserted in the external tank 17′ before extracting the fluid substance therefrom is currently provided.
As evincible, this is for guaranteeing, right from the start inside the tank 11′, an acceptable degree of homogeneity of the product which can thus be supplied without delay and slowing down.
However, such procedure currently in use reveals some drawbacks, such as the required presence of several mechanical agitators so as not to waste time in loading one tank 11 at a time.
Such agitators must then either be stored, wasting space, or sent again along with the tank thus increasing shipment costs.